Laboratory of Microbial Technology, Division of Applied Molecular Microbiology and Biomass Chemistry, Department of Bioscience and Biotechnology, Faculty of Agriculture, Graduate School, Kyushu University, 6-10-1 Hakozaki, Higashi-ku, Fukuoka 812-8581, Japan.
Appl Environ Microbiol. 2011 Nov;77(22):8164-70. doi: 10.1128/AEM.06348-11. Epub 2011 Sep 23.
The culture supernatant of Leuconostoc mesenteroides TK41401, isolated from Japanese pickles, possessed antimicrobial activity against broad range of a bacterial genera and particularly strong activity against Bacillus coagulans, the major contaminant of pickles. An antimicrobial peptide was purified in three chromatographic steps, and its molecular mass was determined to be 6,115.59 Da by electrospray ionization time-of-flight mass spectrometry (ESI-TOF MS). The primary structure of this peptide was determined by amino acid and DNA sequencing, and these analyses revealed that it was translated as a 63-residue precursor. This precursor showed high similarity to the precursor of lactocyclicin Q, a cyclic bacteriocin produced by Lactococcus sp. strain QU 12. The molecular weight calculated after cyclization, which was presumed to involve the same process as in lactocyclicin Q (between L3 and W63), agreed with that estimated by ESI-TOF MS. This peptide was proved to be a novel cyclic bacteriocin, and it was termed leucocyclicin Q. The antimicrobial spectrum of this bacteriocin clearly differed from that of lactocyclicin Q, even though their primary structures were quite similar. This is the first report of a cyclic bacteriocin produced by a strain of the genus Leuconostoc.
从日本泡菜中分离到的肠膜明串珠菌 TK41401 的发酵上清液对多种细菌属具有抗菌活性，特别是对泡菜中的主要污染物凝结芽孢杆菌具有很强的活性。通过三种层析步骤纯化了一种抗菌肽，其分子量通过电喷雾电离飞行时间质谱（ESI-TOF MS）确定为 6115.59 Da。通过氨基酸和 DNA 测序确定了该肽的一级结构，这些分析表明它被翻译为 63 个残基的前体。该前体与乳球菌 QU 12 产生的环状细菌素 lactocyclicin Q 的前体高度相似。推测其环化过程（在 L3 和 W63 之间）与 lactocyclicin Q 相同，所计算的分子量与 ESI-TOF MS 估计的分子量一致。该肽被证实是一种新型的环状细菌素，并被命名为乳球菌素 Q。尽管它们的一级结构非常相似，但这种细菌素的抗菌谱明显不同于乳球菌素 Q。这是首次报道由肠膜明串珠菌属菌株产生的环状细菌素。
